Method of and apparatus for installing a furnace



June 4, 1968 A. M. CASTELLO ETAL 3,386,434

METHOD OF AND APPARATUS FOR INSTALLING A FURNACE 6 Sheetsfihe t 1 Filed March 50. 196'? June 1968 A. M. CASTELLO ETAL 3,

METHOD OF AND APPARATUS FOR INSTALLING A FURNACE Filed March 30, 1967 3 Sheets-Sheet 2 IN VENTORS.

un 4, 1968 A. M. CASTELLO ETAL 3,386,434

METHOD OF AND APPARATUS FOR INSTALLING A FURNACE 1967 3i 3 Sheets-Sheet 3 1 H 'l mlm- JWM ?:%M WI m 3; 33 30- [I I i h! l 11 n Vii? Hi l I m WTMTWIII .H' "In" !,ag;%\"ENTORS-' wfio a I MGMQM United States Patent 7, 3,386,434 METHOD OF AND APPARATUS FOR INSTALLING A FURNACE Anthony M. Castello, Summit, N.J., and Robert R. Cooper, Wichita, Kaus., assignors to The Coleman Company, Inc., Wichita, Kans., a corporation of Kansas Filed Mar. 30, 1967, Ser. No. 627,023 Claims. (Cl. 126-114) ABSTRACT OF THE DISCLOSURE Method and apparatus for installing an outside wall, flush furnace in a trailer or the like, wherein the furnace receptacle is only slightly larger than the furnace itself. A coupling thimble is fitted into a knockout on a bottom plate of a duct boot and secured thereto by bendable tabs. The bottom plate of the duct boot is flat to form a metal-to-metal seal with the furnace under its weight. The thimble is attached to existing ductwork thereby securing the boot bottom plate to the receptacle. The sides and top of the duct boot are then assembled by slipping them into sliding lock seams. The rear ends of the top and sides of the duct boot are inclined inwardly to form a seal with the furnace when installed.

Background In travel trailers of from fifteen to thirty-five feet in length, it is desired that the heating system include a forced air furnace coupled to distribution ductwork in order to achieve optimum comfort and uniform heating throughout the trailer. It is advantageous to install the furnace in an outside wall of the travel trailer, usually just above the floor line. Mounting is accomplished by cutting the outside wall to form a receptacle, inserting the furnace in the receptacle and securing it to the outside wall. This type of furnace is usually referred to as an under-counter furnace because its projection into the trailer can be hidden under cabinets or counters.

When the furnace is a forced air furnace, its receptacle must communicate with a distribution duct in the trailer. The cross-sectional area of the furnace is slightly less than the size of the aperture cut in the trailer wall since a slightly enlarged faceplate of the furnace covers the irregularities of the cut in the wall; and, hence, it is practically impossible to connect the heated air output of the furnace to the trailer ductwork from the outside with conventional meansparticularly when the furnace output is on the bottom. Further, since the furnace usually projects beneath counter work, as mentioned, it is inaccessible from the inside for making the duct connections.

The present invention relates to forced air furnaces; and more particularly, to a method of and apparatus for facilitating the installation of forced air furnaces.

Summary The present invention obviates the problems previously encountered in the installation of wall furnaces by providing a duct boot which fits in the furnace receptacle and is coupled to existing ductwork before the furnace is inserted. Once the duct boot has been joined in the furnace receptacle, the furnace is seated in the duct boot. The duct boot forms a peripheral seal with the furnace for preventing heat loss, and at the same time, couples the furnace output to the trailer distribution duct.

In a particular embodiment, the duct boot comprises a top, bottom, two side walls, and a coupling thimble as separate pieces for shipment or storage; they are easily assembled in the field without the need for any special tools.

3,385,434 Patented June 4, 1968 Other advantages of the present invention will be obvious to persons skilled in the art from the following detailed description accompanied by the attached drawing.

The drawing FIG. 1 is a perspective view of a bottom plate and its knockout for a duct boot according to the present invention;

FIG. 2 is a perspective view of a coupling thimble and gasket for sealing engagement with the bottom plate of FIG. 1;

FIG. 3 illustrates the attachment of the thimble and gasket of FIG. 2 to the bottom plate of FIG. 1;

FIG. 4 illustrates the attachment of the coupling thimble and bottom plate to the existing trailer ductwork;

FIG. 5 illustrates the assembly of the side walls of a duct boot according to the present invention;

FIG. 6 is a close-up view of the sliding lock seam of the duct boot of FIG. 5;

FIG. 7 is an abbreviated elevational View of an assembled duct boot; and

FIG. 8 is a partially broken away front elevational View of a wall furnace inserted in a duct boot.

Description Referring to the drawing, like reference numerals refer to identical elements in the various views. As previously mentioned, an opening in the trailer side for receiving a wall furnace is usually just above the floor line; and it is required that the front side of the furnace be practically flush with the trailer side to avoid a projection from the wall, and that the furnace couple to distribution duct- Work.

In FIG. 1 is shown a duct boot bottom plate, designated generally as 10. The bottom plate 10 comprises a flat sheet 11 which serves as a bearing surface for an inserted furnace, a knockout 12, and a front flange 13 extending at a right angle from the sheet 11 for fastening the bottom plate 10 to the trailer side wall. The sides of the bottom plate 10 (i.e. the segments which run longitudinally of the furnace receptacle) are formed into sliding lock scams or channels, designated respectively as 14 and 15.

As can be seen more clearly in FIG. 6, each of the locking searns 14 and 15 has a hook-shaped cross section for slideably receiving a similarly shaped locking seam on the end of its associated side wall. Also shown in FIG. 1 are knee-shaped spacers 16 which serve to space the bottom plate 10 from the furnace receptacle thereby avoiding a crush of a thimble flange and gasket which fit between the floor of the receptacle and the bottom plate 10.

Referring now to FIG. 2, there is shown a rectangular gasket 17 having an internal periphery equal to the perimeter of the aperture in the bottom plate 10 when the knockout 12 is removed. Also shown in FIG. 2 is a coupling thimble, generally designated as 18. The thimble 18 has a closed rectangular cross section and is adapted to fit into the aperture of the bottom plate 10 when the knockout 12 is removed. On the outside of the thimble 18 is a peripheral flange 19. The gasket 17 seats on the flange 19 beneath the lower surface of the bottom plate 10.

The thimble 18 has an upper set of bendable fingers or tabs 20 which project above the flange 19, and a lower set of similar bendable tabs 21 which extend below the flange 19. The tabs 20 and 21 are formed about the complete periphery of the thimble 18.

The coupling thimble 18 is secured to the bottom plate 10 after the knockout 12 has been removed and after the gasket 17 is seated on the peripheral flange 19, by inserting the upper bendable tabs 20 through the aperture defined by the removal of knockout 12 and bending 3 the tabs outwardly (in the direction of the arrows in FIG. 3) over the bottom plate 10. Hence, the thimble 13 is held to the bottom plate 10 on one side by the flange 19 and sealing gasket 17, and on the other side by the bent tabs 20.

After the thimble 18 has been fastened to the bottom plate 10 of the duct boot, the assembly is placed in the furnace receptacle so that the flange or lip 13 abuts the external side wall of the trailer, and the downward-depending tabs 21 project into a distribution duct, which is shown by the cut away portion in FIG. 4 and designated by reference numeral 22. As can be seen, the trailer distribution duct 22 runs parallel to the trailer floor, and it is located just beneath it so that the tabs 21 on the thimble 18 may be bent into the duct by finger motion as is shown in FIG. 4. In this manner, the unitary structure of duct bottom plate, sealing gasket and coupling thimble are secured to the trailer distribution duct.

The side walls of the duct boot are shown in FIG. and designated respectively as 25 and 26. As can be seen from the drawing, the side walls 25 and 26 are provided with upper and lower sliding lock seams 27. The side walls 25 and 26 are assembled to the bottom plate by sliding their associated lock seams in the direction of the arrow as shown in FIG. 5. The side walls 26 and of the duct boot are further provided with inclined back surfaces 29 and 28 for sealingly engaging the sides of a furnace when it is inserted. For clarity of illustration of the sliding lock seams, it is not shown in FIG. 5, but the side walls 25 and 26 are each provided with lips or flanges 30 and 31 (see FIG. 7) for attaching to the exterior side of the travel trailer.

The duct boot also has an upper wall, 32 in FIG. 7, comprising a generally flat plane 33, a front flange 34 for attachment to the exterior wall of the trailer, a downwardly-inclined rear surface 35 for sealing the top of an inserted wall furnace, and side sliding lock seams 38 for locking with the upper sliding lock seams 27 of side Walls 25 and 26. The front flanges 13, 30, 31 and 34 are then fastened to the trailer by screws 340.

In FIG. 8 is shown, partially broken away, a faceplate of a furnace, designated as 36 with a peripheral sealing flange 37. When a furnace is fully inserted in its receptacle, the peripheral flange 37 engages the exterior side wall of the trailer for sealing the front of the furnace. The previously-mentioned spacers 16 attached to the lower surface of the plate 11 of the bottom plate It) space the bottom plate of the duct boot away from the trailer floor so that the weight of the furnace does not crush the flange and gasket of the thimble which are inserted between the floor and the bottom plate It).

It will be appreciated that the trailer distribution duct need not communicate with the duct boot only through is bottom plate, but additional knockouts may be provided in the side walls of the furnace and duct boot for coupling with distribution ducts. In this case it will be noted that it is possible to have side telescoping extensions attached to the duct boot which would align with the air output of the furnace since there is some room on either side of the furnace after it is installed for manipulation of a hand. However, the thimble as described above has been shown to be the most advantageous when the trailer duct attachment is beneath the furnace since it has been found that a very good seal between the duct boot and the furnace is the metalto-metal seal provided between the bottom plate 10 and the bottom surface of the furnace with the weight of the furnace bearing down to force them in close contact. The inwardly depending flanges at the back of the sides and top of the duct boot are desirable for sealing the furnace on the other sides. As mentioned above, the flange of the faceplate seals the front.

It will be obvious to a person skilled in the art that similar structure may be substituted for that which has been illustrated without departing from the principle of the present invention; and it is, therefore, intended that such modifications be covered as they are embraced within the spirit and scope of the appended claims.

We claim:

1. Method of installing a furnace in an outside wall confining a space to be heated, said wall defining a receptacle slightly larger than the cross-sectional area of said furnace and communicating with a distribution duct comprising: attaching a coupling thimble to a duct boot plate; inserting the plate in the opening with the thimble extending into the duct; coupling said thimble to said distribution duct; and assembling three duct boot sides to said first duct boot side to form a closed channel for sealingly receiving said furnace.

2. The method of claim 1 wherein said distribution duct is on the bottom of said receptacle and the bottom plate of said boot defines an aperture for aligning with the furnace output, said step of attaching said coupling thimble to said duct boot plate comprising: inserting a coupling thimble having a peripheral flange and depending bendable tabs through said aperture in said bottom plate until limited by said flange; and bending the inserted tabs outwardly to engage said bottom plate.

3. The method of claim 2 wherein said coupling thimble includes second depending bendable tabs extending away from said aforementioned tabs, further comprising: inserting said unitary assembly of bottom plate and thimble into said receptacle with said second tabs projecting into said distribution duct; and then bending said second tabs outwardly against the side of said distribution duct.

4. The method of claim 3 further comprising: inserting a sealing gasket between said peripheral flange of said thimble and said bottom plate, and spacing said bottom plate from the bottom of said receptacle to avoid crushing of said flange.

5. A boot for insertion into a wall-furnace receptacle communicating with a distribution duct, said receptacle receiving a furnace defining an output for heated air, comprising: a closed channel defining a flat bottom plate, first and second side plates and a top plate for receiving said furnace; means associated with said side plates and said top plate for sealingly engaging an inserted furnace; and coupling means attached to said channel for sealingly coupling said furnace output to said distribution duct through said channel.

6. The boot of claim 5 wherein said channel defines an aperture and said coupling means comprises a thimble having a peripheral flange for engaging said channel about said aperture; and a set of bendable tabs about its periphery for connecting to said channel.

7. The boot of claim 5 wherein said channel side plates, top plate and bottom plate have mating sliding lock seams for forming a unitary, closed channel.

8. The boot of claim 7 wherein said side plates and said top plate define inclined surfaces for sealingly engaging an inserted furnace.

9. The boot of claim 5 wherein said furnace has a metal casing, said heated air output is in the base of said furnace, and wherein said bottom plate defines an opening in register with said furnace output when said furnace is inserted in said boot, said coupling means comprising a gasket, and a thimble having a peripheral flange for supporting said gasket and longitudinally-extending bendable tabs on either side of said flange, the tabs on one side of flange adapted for cooperation with said flange to secure said thimble to said boot, the tabs on the other side of said thimble adapted for engaging said transfer duct.

19. In a system for heating a confined space including a forced air furnace, a receptacle defining an aperture slightly larger than said furnace for receiving said furnace, and a distribution duct communicating with said 5 6 receptacle, the combination with said receptacle of a References Cited closed conduit tor insertion therein including a flat bot- UNITED STATES PATENTS tom plate and inclined edges for seahngly engaglng th sides and top of an inserted furnace, and a coupling 3,067,735 12/1962 Albert 126-110 3,283,753 11/1966 Boddettet a1 12.6-110 thimble attached to said conduit having means for receiving the forced air from said furnace and coupling it through said conduit to Said duct. JAMES W. WESTHAVER, Plzmary Exammer. 

